Abstract: Project Description The Hispanic/Latino (H/L) population in the US has a disproportionately higher prevalence of cardiovascular disease (CVD) risk factors. The proposed K01 Mentored Career Development Award to Promote Faculty Diversity will facilitate Dr. Rosalba Hernandez in establishing an independent research career with expertise in therapeutic psychosocial interventions for H/L adults with poor cardiovascular health. But, successful attainment of status as an independent investigator requires further training. Training objectives aim to increase her expertise in: clinical trials design; statistical methodology for randomized trials; physiological mechanisms of the brain-heart interaction and non-invasive cardiology; delivery of positive psychology interventions; and advanced skills in research dissemination and enhanced professional development. Training takes full advantage of the candidate's strong institutional support and environment at the University of Illinois. Observational studies demonstrate a robust association between positive psychological well-being (or `emotional well-being') and cardiovascular health, but experimental testing is required to assess whether interventions geared toward improving psychological well-being result in enhanced heart health. This proposal consists of two interrelated studies that together explore the link between psychological well-being and cardiac- health, with nuanced exploration of biobehavioral mechanisms. Using data of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) (n=16,415), we will examine the cross-sectional and prospective association between positive emotional well-being (e.g., optimism) and cardiovascular health, with in-depth exploration of plausible intermediaries such as autonomic nervous system activity, inflammatory biomarkers, and endothelial function. The large and heterogeneous HCHS/SOL cohort data allows identification of effect modifiers such as country of origin and level of acculturation, which is often not feasible in the context of a small experimental trial. We additionally propose implementation of a pilot cluster-randomized trial. A total of 126 H/L adults with uncontrolled hypertension will participate in a pilot cluster-randomized trial testing the efficacy of a positive psychology (PP) intervention. Efficacy of the PP intervention versus an attentional control arm will be assessed primarily for blood pressure, and secondarily for emotional well-being, health behavior adherence, heart rate variability, and C-reactive protein. The proposed studies will provide preliminary data to conduct a larger fully-powered RCT with pursuit of funding via an R01 mechanism. Dr. Hernandez will obtain critical skills through interdisciplinary mentorship from experts in cardiovascular epidemiology, non-invasive cardiology, and clinical psychology. Experiences gained from the proposed K01-related activities will provide the necessary competences for Dr. Hernandez to become a successful independent investigator.